The utility of alkoxysilanes as masonry water repellants (MWR) is widely known. Compositions currently in use employ solutions of silanes in various solvents such as alcohol (U.S. Pat. No. 3,772,065 dated 13 Nov. 1973 and U.S. Pat. No. 4,342,796 dated 3 Aug. 1982) or hydrocarbons (U.S. Pat. No. 4,525,213 dated 25 June 1985). Principle limitations of the solvent type compositions include the toxicity and flammability of the solvents employed. In the case of the low molecular weight alcohols, e.g., isopropanol, the rapid evaporation rate limits the extent of penetration and curing of the silane in the substrate. Reference may also be had to U.S. Pat. No. 2,683,674 dated 13 July 1954 showing the use of alkyl polysiloxanes in a volatile solvent solution.
Aqueous solutions of hydrolyzed silanes have been reported as effective masonry water repellant compositions. (See U.S. Pat. No. 4,517,375 dated 14 May 1985).
Aqueous emulsions of organopolysiloxane oils (See U.S. Pat. No. 4,476,282 dated 9 Oct. 1984) and an aqueous dispersion of silicone resins (See U.S. Pat. No. 4,529,758 dated 16 July 1985) have also been reported. These materials are quite different from the silane compositions of the present invention. There is a need for a water based composition which is stable for a long period of time and which is highly effective as a masonry water repellant composition.
By the term "masonry" as used herein, is meant any porous inorganic substrate, particularly building compositions and including but not limited to structural ceramics such as common brick, paving brick, face brick, sewer pipe, drain tile, hollow block, terra cotta, conduits, roofing tile, flue lining, cements and plastics such as Portland cement, calcined gypsum products, i.e., molding and building plaster and stucco, magnesia cement, isulation products such as electrical insulators, porcelain spark plugs, etc., thermal and insulators (diatomaceous earth brick). The present invention is particularly applicable to masonary, i.e., to all articles and architecural structures such as porous ceramic materials including stone, brick, tile, artificial stone, abode, etc., and to ceramic articles, particularly masonry units, e.g., brick, pieces of stone, etc., which are generally held together or made a single mass by mortar, plaster or earth.
The masonry materials also include concrete and reinforced concrete such as found in roadways, bridge decks, airport runways, parking garage decks, and other concrete building structures.
The masonry materials which can be treated in accordance herewith are preferably dry when treated with the waterproofing compositions, although they may be wet. In the case of settable masonry materials, the compositions of the present invention may be incorporated in the preset mixture, for example, into a concrete mix prior to casting and setting.